Oil burner



July 18, 1944. c. L, COOPER 2,353,880

OIL BURNER Filed Nov. 2, 1943 67742455 1. Coo s/2,

Patented July 18, 1944 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to oil burners of the pot type as distinct from oil burners employing jets or blowers for vaporizing the oil and mixing it with air for complete combustion.

In the pot type burner, a pool of oil is maintained in the bottom of a bowl having air inlet apertures in its side walls, and the oil is vaporized by heat radiated down onto the oil pool, the vapor being mixed with air drawn in through the apertures by bafiles within the bowl so that substantially complete combustion is effected.

Pot type oil burners have great advantage for small installations in that they are relatively simple and inexpensive and do not require auxiliary power equipment, such as an electric motor. However, a disadvantage of the conventional pot type burner is that its range of operation is limited, such devices being incapable of maintaining proper combustion if attempt is made to operate them at too low a rate.

An object of the present invention is to provide a pot type oil burner that is capable of maintaining a flame when the rate of oil supply is reduced to a very low value, whereby a low heat can be provided, and whereby a pilot flame can be maintained with small consumption of oil during periods when little or no heat is desired.

Another object is to provide a simple, inexpensive and rugged oil burner of the pot type that is capable of maintaining clean combustion at a very slow rate of oil consumption.

I accomplish the foregoing objects, together with more specific objects and advantages, by providing in combination with the usual bowl or pot a small auxiliary pot which is positioned against the side of the main pot and connected to it by a relatively large passage, and feeding the oil through the auxiliary pot into the main pot.

The auxiliary pot is closed at the top and provided with air inlet apertures in its side walls so that when the rate of oil supply is low, all the oil is vaporized and mixed with air in the auxiliary pot and burns therein, the products of combustion escaping through the interconnecting passage into and through the main pot. However, when the rate of supply of the oil is increased beyond a predetermined minimum, it is incapable of being burned in the auxiliary pot and it overflows through the interconnecting opening into the main pot where it is immediately ignited by the flame issuing from the auxiliary pot. Thereafter, the major combustion occurs in the main pot, as in the previously known pot type burners.

A full understanding of the invention may be had from the following detailed description with reference to the drawing in which:

8 Fig. 1 is a front elevation view of an assembly of main and auxiliary pots in accordance with the invention;

Fig. 2 is a vertical section taken in the plane IIII of Fig. 1 and showing, in addition, a portion of the baffle which isolates the top discharge opening of the pot from the air inlet apertures of the pot; and

Fig. 3 is a perspective view of the auxiliary pot with the covers removed.

In the drawing, the main pot ID of a burner in accordance with the invention is shown supported from its top in a circular aperture ll of a plate l2 which forms a portion of the furnace or heater in which the burner is employed. Thus burners of the type here described are employed in various types of heating devices, including space heaters or stoves, water heaters and the like. Such arrangements are old and an installation of a pot type burner in a stove or space heater is shown in my prior Patent No. 2,244,766, issued June 10, 1941. That patent discloses a partition plate corresponding to the plate II in Fig. 2, and if further information is desired relative to the auxiliary structure that may be employed with the present invention, reference may be had to the aforementioned patent, it being understood that the pot structure of the present invention can be substituted for the pot shown in the earlier patent.

As shown, the main pot I0 has integral bottom and side walls, and the top is partially closed by a lid member l3 having a downwardly extending flange M which is reentrant in the top of the pot l0 and secured to the pot by screws [5. The lid I3 also has an outwardly extending edge or flange 16 which, in the particular arrangement shown in Fig. 2, rests on the edge of the partition plate l2 and supports the pot. The pot is provided on its interior with a plurality of helical bafiles I! and an annular ballle l8 which function to promote clean combustion by radiating heat to the liquid oil in the bottom of the pot and by inducing mixing of the oil vapor and the combustion air which enters through numerous apertures IS in the side wall of the pot.

The exact arrangement and proportioning of the battles and the air inlet apertures does not constitute a part of the present invention and detailed information relative thereto may be had from the aforementioned Patent No. 2,244,766.

Positioned immediately in front of the main pot I0 is an auxiliary pct 20 which is substantially rectangular in shape, being preferably approximately four inches wide and high and approximately one and one-half inches in depth (measured from front to rear of the heater or from left to right with reference to the sectional view of Fig. 2).

The auxiliary pot has in its rear side a relatively large opening 2i defined by a rearwardly protruding annular flange 22 which is connected in fluid-tight relation to the main pot l surrounding an opening 23 therein which registers with the opening 2|. It is convenient in practice to weld the auxiliary and main pots together as indicated at 24.

To permit access to the interior of the auxiliary pot for cleaning purposes and the like, the top may consist of a removable plate 25 secured in place by a pair of screws 26 at opposite ends thereof.

A lighting aperture 2'! is provided in the front wall of the auxiliary pot at a level substantially above the maximum level that oil may normally attain in the device. This lighting aperture 21 is normally closed by a slide cover 28 pivotally connected by a screw 29 to the front wall of the auxiliary pot. A helical spring 3| compressed between the head of the screw 29 and the slide plate 28 urges the plate against the wall of the auxiliary pot to frictionally retain it in either opened or closed position. The spring 3| may be partially or completely enclosed in a housing 30.

Th front wall of the auxiliary pot is provided near its lower edge with a tapped opening 32 for receiving an oil supply nipple 33 which may be connected by a cross fitting 34 and a nipple 35 and a control valve 36 to a supply pipe 31. The end of the cross fitting 34 opposite to the nipple 33 is closed with a plug 38 which can be removed for clean-out purposes, and the end of fitting 34 opposite the nipple 35 has screwed into it a short standpipe 39 through which air can enter the nipple 33 and the burner along with th oil.

The auxiliary pot 20 is provided with six vertical rows of air inlet apertures 40, each row including three holes. One row of holes is positioned in each of the narrow side Walls of the pot, two rows in the front wall on each side of the lighter opening 21 and two rows in the rear wall substantially opposite the rows of apertures in the front wall.

The structure described functions in the following manner. When the pot is operating at normal load, the valve 36 is opened to such an extent as to admit a sufficient stream of oil to overflow from the auxiliary pot into the main pot substantially as indicated at 4| and oil is vaporized from the resultant pools in both the auxiliary and main pots, the vapor rising, mixing with air drawn in through the air inlet apertures 40 in the auxiliary pot and inlet apertures l9 in the main pot and burning in both pots, it being understood that whatever appliance the device is mounted in is of such a nature as to create a draft to draw the products of combustion out through the discharge opening 42 in the top of the main pot.

During such operation, combustion in the auxiliary pot may be relatively incomplete but since all of the gases flow from the auxiliary pot through the opening 2| into the main pot, any incompletely burned fuel in the mixture leaving the auxilian pot will be mixed with additional air and burned in the main pot.

When the heat is to be reduced to a low value, or it is desired to merely maintain a pilot flame with the generation of as little heat as possible, the valve 36 is partly closed to reduce the flow of oil to such a point that it is all consumed in the auxiliary pct 20 and does not overflow through the passage 2| into the main pot. Obviously, the main flame in the main pot goes out because there is no fuel supply to sustain it. However,

the small amount of oil admitted into the auxiliary pot continues to burn efficiently because only a small flame is required to maintain the auxiliary pot at an efficient operating temperature.

A certain amount of heat is necessary to the satisfactory operation of any pot type burner because the vaporization of the oil is accomplished substantially entirely by heat radiated or conducted from the upper portion of the pot to the oil pool in the bottom thereof. or course, the products of combustion and a portion of the flame generated in the auxiliary pot during idling operation pass through the opening 23 into the main pot In Where they are mixed with additional air entering through the apertures I9 and are discharged through the opening 42.

When the oil supply is increased following a period of idling operation, the oil immediately overflows from the auxiliary pot into the main pot, reestablishing the pool of oil therein and the oil is immediately ignited in the main pot by the flame which still continues to issue from the auxiliary pot through the opening 2|.

Although for the purpose of explaining the invention a specific embodiment thereof has been described in substantial detail, it will be obvious to those skilled in the art that various departures from the exact construction shown can be made without departing from th invention which is to be limited only to the extent set forth in the appended claims.

I claim:

1. A pot type oil burner of the type described, comprising: a main pot having an imperforate bottom wall for retaining a pool of oil therein, a lateral wall having air inlet apertures therein, and a top wall having an outlet opening; and a pilot pot smaller than and positioned alongside said main pot and connected thereto by a discharge passage, said pilot not having bottom, lateral and top walls, the lateral wall having air inlet apertures and one wall having an oil inlet opening, the lower edge of said discharge passage being positioned adjacent the bottom of said pilot pot, whereby oil flowing into said pilot pot in excess of that consumed therein overflows into the main pot.

2. An oil burner as described in claim 1 in which the bottom walls of the pilot and main pots are at substantially the same level.

3. A burner as described in claim 1 in which the lateral wall of said pilot pot has a lighter opening therein, and a door for closing said opening.

4. A pot type oil'burner of the type described, comprising: a main pot having an imperforate bottom wall for retaining a pool of oil therein; a lateral wall having air inlet apertures therein and a top wall having an outlet opening; and a pilot pot smaller than and positioned alongside said main pot and connected thereto by a discharge passage, said pilot pot having bottom and top walls, a rear wall adjacent said main pot, a front wall juxtaposed thereto and side walls interconnecting the rear and front walls, the front, rear and side walls having air inlet apertures, said discharge passage extending through said rear wall, and said front wall having an oil inlet opening, the lower edge of said discharge passage being positioned adjacent the bottom of said pilot pot, whereby oil flowing into said pilot pot in excess of that consumed therein overflows into the main pot.

CHARLES L. COOPER. 

